Contractor Exam Questions And

CA C12 Earthwork And Paving Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• What is the primary purpose of subgrade preparation in paving

projects?

• To improve aesthetics
• To reduce material cost
• To provide a stable foundation for pavement
• To prevent drainage

Rationale: Proper subgrade preparation ensures the pavement will

have a stable base, reducing risk of failure.

• Which of the following is the most suitable soil type for subgrade in

heavy traffic areas?

• Clay
• Sandy silt
• Granular soil (well-graded gravel or sand)
• Peat

Rationale: Granular soils provide good drainage and compaction

properties, ideal for supporting heavy loads.

• What is the standard method to determine soil compaction in

earthwork?

• Visual inspection
• Water content only
• Proctor test
• Soil color test 1 / 3

Rationale: The Proctor test measures soil compaction and optimum

moisture content, ensuring the desired density is achieved.

• Which equipment is commonly used for fine grading before paving?
• Bulldozer
• Backhoe
• Motor grader
• Scraper

Rationale: Motor graders provide precise leveling and slope control,

essential for final subgrade preparation.

• What is the minimum compaction requirement for subgrade under

asphalt pavement according to most standards?

A. 75%

B. 80%

• 95% of maximum dry density (Proctor)

D. 100%

Rationale: Achieving 95% of maximum dry density ensures adequate

support and reduces pavement settlement.

6. In earthwork, a “cut” refers to:

• Removing soil from an area to lower the ground level
• Adding soil to raise the ground
• Excavating for utilities only
• Leveling with a roller

Rationale: “Cut” operations involve removing soil to reach the

required design elevation.

• What is the function of a geotextile in paving?
• Decorative purposes
• Absorbing water
• Separation, filtration, and reinforcement of subgrade
• Insulation

Rationale: Geotextiles prevent mixing of subgrade and base

materials, improving pavement life.

• Which type of asphalt mix is most suitable for high-traffic roads?
• Open-graded mix
• Dense-graded hot mix asphalt (HMA)
• Cold mix asphalt
• Surface treatment 2 / 3

Rationale: Dense-graded HMA provides strength and durability for

heavy traffic areas.

• What is the typical thickness range of asphalt surface courses in

commercial roads?

• 25–50 mm
• 50–75 mm
• 75–100 mm
• 100–150 mm

Rationale: This thickness provides adequate wear resistance and load

distribution for standard commercial roads.

• When compacting subgrade, which factor most influences

compaction efficiency?

• Soil color
• Moisture content
• Air temperature
• Wind speed

Rationale: Moisture content affects soil particle cohesion and density,

critical for achieving maximum compaction.

• What is “proof rolling” in earthwork?
• Painting road markings
• Applying asphalt
• Testing subgrade strength using a loaded roller
• Trimming vegetation

Rationale: Proof rolling identifies weak areas in the subgrade that

need correction.

12. The CBR (California Bearing Ratio) test measures:

• Soil color
• Soil strength and bearing capacity
• Soil permeability
• Moisture content

Rationale: CBR is a standard test to determine suitability of soil for

road pavement design.

• Which type of roller is most effective for granular subgrade

compaction?

• Pneumatic roller
• Vibratory steel drum roller
• Hand tamper
• / 3